Abstract:

The paper aims to solve the problems of severely influenced flue-cured tobacco production by weeds and low efficient artificial weeding. Based on the investigation of weed community in the field of flue-cured tobacco in Xiangxi Autonomous Prefecture, three herbicides including dimethyl-pentaphenol, sulfonyl-sulfonyl and jinquaoling were selected for weed control experiments. The results showed that the seven dominant species of upland weeds in flue-cured tobacco were Artemisia lavanduaefolia, Eclipta prostrata, Xanthium sibiricum, Polygonum lapathifolium, Sids alnifolia, Echinchloa colonum and Lepochloa chinensis. Before transplanting tobacco seedlings, the use of 33% dimethoxypene emulsion 1500-3000 mL/hm ² had a good control effect on annual single and dicotyledon weeds, but the control effect on perennial weeds was not ideal, and it was harmful to tobacco seedlings and inhibited their growth and development. As a pre-bud herbicide, it should be applied carefully in the production of tobacco. After removing the film from flue-cured tobacco, a directional spray of 25% sulsulfuron 52.5 g/hm² was applied on ridge furrow. Single application could effectively prevent single and dicotyledon weeds except radix aconitae, and had little effect on the growth and development of flue-cured tobacco. After removing the film of flue-cured tobacco, 8.8% jingquehaling 525 mL/hm² was used, which had good control effect on single cotyledon weeds and a long duration of efficacy, while on dicotyledon weeds, the growth and development of flue-cured tobacco was safe. The synergistic effect was not obvious when sulprosulfuron was mixed with quinoxaline. Once herbicide harm is found in the tobacco seedlings after transplanting to the seedling stage, the effects of pesticide damage can be alleviated or removed by changing the seedlings.

Key words: Flue-cured Tobacco, Herbicides, Weed Control Effect, Hytotoxicity, Agronomic Traits